Ventilación mecánica no invasiva en el periopertorio para el paciente con obesidad. Una revisión narrativa

Abstract: This narrative review highlights the relevance of noninvasive mechanical ventilation (NIV) as an essential intervention to optimize respiratory safety in obese patients during the perioperative period, a population characterized by markedly reduced functional residual capacity, increased alveolar collapse, and hypoventilation that elevate the risk of critical hypoxemia. The analyzed evidence demonstrates that CPAP (Continuous Positive Airway Pressure) and BiPAP (Bilevel Positive Airway Pressure) improve oxygenation by enhancing alveolar recruitment and prolonging the safe apnea time, offering superior benefits compared with conventional oxygenation techniques. During the preoxygenation stage, multiple trials confirm that positive pressure reduces the incidence of peri-intubation hypoxemia, with greater impact in patients with elevated BMI or obstructive sleep apnea (OSA). During anesthetic induction, the application of CPAP between 7 and 10 cmH2O or BiPAP with an appropriate IPAP–EPAP (Inspiratory Positive Airway Pressure–Expiratory Positive Airway Pressure) gradient improves respiratory stability, reduces ventilatory effort, and prevents the rapid desaturation characteristic of this population. In the postoperative period, contemporary studies such as EXTUB-OBESE demonstrate that early application of NIV reduces respiratory failure and increases reintubation-free time, with particularly pronounced benefits in patients with morbid obesity. Additionally, BiPAP offers advantages in the presence of hypoventilation or hypercapnia, whereas CPAP is more effective when atelectasis predominates. Based on the findings of this review, it is recommended to use NIV systematically during preoxygenation in obese patients, select the modality according to the predominant pathophysiology, initiate CPAP and BiPAP with safe and titrated parameters guided by clinical response, and implement prophylactic use after extubation in patients with BMI ≥ 40 kg/m² or high respiratory risk.